what your accountant told you is technically correct. I had posted on this subject some weeks ago.
However, it is possible to have two porfolios: one for trading, and the other one for investments. The trick is, for that to work, you will have to have your structural groundwork laid properly from the beginning. And, some may ask "how do I do that". The answer to that is, that is what you are paying your accounatnt for :-)
As always, with subject of this nature, your individual circumstance is critical in the structuring of your trading/investment activities. It will be in your best interest to seek further professional advice.